Convey coolant to form an engine cooling circuit, maintain a system pressure of 100-150kPa to prevent boiling, withstand temperature differences of -40 ℃ to 120 ℃, and resist vibration and coolant corrosion. Quality: EPDM material, wall thickness of 3-5mm, sealed interface, 200kPa pressure holding without leakage. Transfer coolant to achieve a "heat absorption heat dissipation" cycle, avoiding system pressure leakage and resisting cabin temperature changes, vibrations, and chemical erosion. Quality: Made of EPDM or silicone, resistant to high temperatures up to 150 ℃, with a clamp attached to the interface, tested for no cracks, and good elasticity after aging.